Hygrometer.



"No. 834,660. PATENTED OCT. 30, 190B.

I J. GOWLING.

HYGROMETER.

APPLICATION FILED JULY 21. 1906.

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INVENTOR Jamar wwlzky ATTORNEY No. 884,660. PATENTED 001'. so, 1906.

J. GOWLING. HYGROMETER.

APPLICATION FILED JULY 21. 1906.

2 SHEETS-SHEET 2.

INVENTOR Jamzeu" wa lz'lzg BY M ' ATTORNEY UNITED STATES PATENT OFFICE.

JAMES HQOWLIYNG, or NEW YORK, n. Y. HYGROMETER- Specification of Letters Patent.

Patented Oct. 30, 1906.

Application filed July 21, 1906- Serial No. 327,141-

lb all whom it may concern.-

tain new and useful Im rovements in Hygrometers, of which the' ollowing is a specication.

The invention relates to improvements in hygrometers; and it consists in the novel' features, arrangements, and combinations of parts hereinafter described, and particularly pointed out in the claims.

The purpose of my invention is to provide means which may be easily understood and operated and used without liability of mistake for determining with the aid of a wet and a dry bulb thermometer the dew-point, relative humidity, and weight in grains per cubic foot of aqueous vapor present in the atmosphere.

In carrying out my invention I provide an instrument comprising a wet and a dr bulb thermometer and a series of setsv of ta les in, dial form, each set adapted to a degree repre sented by-the dry thermometer and to the conditions which may prevail under the showing at the same time of the wet-bulb thermometer and each set being capable of rotary movement, so that the pro er table ooincidin with the indications o the dry and wet ulb thermometers may be moved to a definite fixed position and easily read. I prefer to arrange the sets of tables for the different degrees represented on the dry-bulb thermometer one after another upon a strip of flexible fabric, which-may be caused to travel upon rollers, so that the proper set of tables for the degree represented for the drybulb thermometer may be brought before an openin in the dial orface of the instrument. The re] ers carrying the flexible strip I preferably mount in a frame or box which after the proper set of tables has been brou ht to the .face of the instrument may be axial y rotated for the purpose of bringing the-table corresponding with the showing of the wet-bulb thermometer into line with a fixed indexfin er. The tables for each set are arranged ra ially or in dial or wheel form, so that upon the proper turning of the frame or box carrying the flexible strip the table desired to be used may stand vertically at the upper portion of the instrument and be easily read.

My instrument is simple in construction; and one of its principal objects is to enable a person in a very simple easy manner withto mistake to out calculation or liabilit readily ascertain the relative humidit and other facts contained in hygrometer-ta les.

The invention will be fully understood sented, reference being had to the accompanying drawings, in which- Figure 1 is a front elevation, partly broken away, of a hygrometer or hygroscope constructed in accordance with and embodyin my invention; and Fig. 2 is a central vertica section of same on the dotted line 2 2 of Fig. 1. In the drawings, A denotes the eneral frame of the machine, comprising the ase B,

standards C C, a front face or dial ortion D,

and, a rear supporting standard or racket E, from which and between the same and the face D is pivotally mounted the box F, within from the detailed description herein after prewhich upon rollers G G HH is mounted the flexible strip I, bearing the sets of tables,

which as the strip is caused to travel from the upper to the lower rollers or from the lower to the upper rollers ma be made to appear in the opening J, forme in the face D, one set of said tables being illustrated in position in Fi 1. The box F is secured upon a pivot-bolt and carries a forwardly and outwardly extending arm L, which projects through the circular opening J and is adapted to be moved along the edges thereof.

Upon the face D, I provide a fixed indexfinger M and also a circular dial N, encompassing the opening J and bearing a series of equally-spaced numerals running, referably, from 1 to 18, inclusive, which guide the user of the device in the movement of the arm L for setting the box F and the set of tables which may then be at the openin J in proper position with respect to the ed indexfinger M.

Upon the standards 0 C are mounted the dry and wet bulb thermometers O P, respectively, these thermometers being of wellknown character and construction and requiring no special description. The strip of fabric I may be of any length desired and is fastened at its ends to the rollers G G and adapted to travel over the rollers H H, which maintain a definite stretch of the fabric parallel with the front of the or from the lower roller G to the upper roller G.

. The strip of fabric I bears a series of sets of tables arranged radially in radial spaces upon a circular field at whose center is provided a circular space bearing a numeral, as shown in Fig. I, each of the tables being adapted to stand vertically below the stationary index-finger M when brought to that point by the manual rotation of the box F. The large numerals at the center of the sets of tables, as 70 in Fig. 1, correspond with the degrees appearing on the dry thermometerL- One set of the tables is shown in Fig. 1'; but the strip I may bear as many sets of tables as maybe desired, each set corresponding in general arrangement with the set shown in Fig. 1 and differing therefrom only in the numerals displayed thereon. In Fig. 1 is shown the set of tables which must be used when the dry bulb thermometer stands at 70,and the'other sets of tables carried by the strip I will each bear the proper tables for use with the successive indications that may be given by the dry-bulb thermometer. The sets of tables are each in dial form, as shown in Fig. 1, and I will preferably provide the strip with fifty of these sets of tables arranged for use with the dry and wet bulb thermometers and respectively adapted to, say, from fifty to one hundred degrees, inclusive, on the dry thermometer, the sets of i tables necessarily varying in their numerals in accordance with the degree of the dry thermometer that may be shown at the center thereof.- With reference to Fig. 1 it will be seenthat the radial tables diiler in their indications from each other and are in line with the numerals on the circular dial N and that each of said tables comprises four lines of numerals. The inner numeral of each of the radial tables is for use in connection with the wet-bulb thermometer, the next outer numeral represents the dewpoint, the next outer numeral denotes the percentage of humidity, or, as commonly termed, the relative humidity, and the outer line of numerals of each table gives the weight in grains per cubic foot of aqueous vapor.

In the employment of 'the hygrometer the user will first ascertain the degree represented on the dry-bulb thermometer and then effect the travel of the strip I until the set of tables bearing the degree shown by said thermometer appears at the opening J in the front of the instrument, and we may assume that in the present instance said thermometer stood at and the user had caused the travel of the strip I until the set of tables bearing the numeral 570 at the center thereof appeared at the opening J, this being the condition represented in Fig. '1. The purpose of the instrument being to determine the relative humidity or the dewpoint or the weight in grains per cubic foot of I aqueous vapor, or all of these facts, the user will then observe the wet-bulb thermometer, I finding in the present instance that it stands at 69, and note that there is but one degree of difference between the wet and dry thermometers, and in such instance he will allow the arm L to remain at the numeral 1 on the dial N, since under such condition the proper table will: be directly below the fixed index-finger M, the 69' in said table corresponding with the wet-bulb thermometer, which is an assurance to the user that the proper table is below said index-fin ger M, and said table giving the dew-point as 69, the relative humidity ass 95, and the weight in grains per cubic foot of aqueous vapor as 7.581. If, however,- instead of the wet-bulb thermometer standing at 69 it had stood at 60, the user, observing that there were ten degrees of difference between the wet and dry thermometers, would grasp with his finger and thumb the arm L and move the same along the edge of the openin J just ten points, or until 'said arm reach the numeral 10 on the circular dial N, the eflect of this be'in that the box F would be rotated on the bol t K, and the table lettered R would be turned until it stood vertically directl below the stationary index-finger M, sai table at its then lower figure showing the numeral 60, corresponding with the degree given on the 'wetbulb thermometer,

at its next outer numeral 53 disclosing the dew-point, at its next outer numeral 56 giving the relative humidity, and at its outer or top indication 4.469 giving the weight in grains per cubicfoot of aqueous vapor. Whenever the dry thermometer stands at 70, the set or wheel of radial tablcs hearing at its center the numeral 70 will be made use of regardless of how the wetbulb thermometer may at the time stand. In Fig. 1 I illustrate the relative positions of the parts when there islbut one degree of difference between the Wet and dry bulb thermometers and have explained the simple step to be performed when there are ten degrees difierence between the wet and dry bulb thermometers. The user of the instrument will always ascertain the difference between the showings of the wet and drybulb thermometers and rotate the box F to a corresponding extent, so as to bring the table proper for the degree shown by the wet-bulb thermometer directly below the index-finger M, and the table thus presented below said index-finger will always give the dew-point, relative humidity, and weight in grains per cubic foot of aqueous vapor under the conditions determined by the dry and wet bulb thermometers.

It will beobserved that the o eration of the instrument is a very siinp e one and easily understood and that it is practically xutilize the arm L as the index-arm forfthis impossible for any one to make any mistakein ascertaining the relative humidity, dewpoint, and weight in grains. The inner numeral of each table corresponding with the degree shown by the wet-bulb thermometer is always an assurance that the proper table is below the index-finger M, and the presence of this numeral Would be a suflicient ide to many persons in turning the box F to the correct position Without the employment of the circular dial N; but for completeness I prefer to make use .of the circular dial N and circular dial and alsoas the means for rotating the box F, carrying the strip I, said box being simly a frame supporting the rollers carrying t e strip I and not necessarily being closed atits top and bottom but preferably closed for the urpose of excluding light and dust from the fabric I.

My invention thus presents a simple and easily-operated means capable of ready and accurate use for determinin the deW-point, relative humidity, and weig t in grains per cubic footof a ueous vapor under any of the various conditions represented by the dry and wet bulb thermometers, leavin nothing 'for mathematical calculation or re erence to othertables and avoiding any likelihood of the user of the instrument making any mistake in his reading thereof, which is a matter of vital importance since in instruments heretofore rovided for determining relative humidity t e user, due to the complexity of the reading parts, is liable to make mistakes in the reading thereof.

I What I claim as my invention, and desire lto secure by Letters Patent, is

1. In an instrument of the character described, a and a wet bulb thermometer, and a series of sets of hygrometer-tables each adapted to be held in an exposed position and each adapted to a definite reading of the drybulb thermometer, each of said sets being in dial form and bearing acharacter denoting the reading of the dry-bulb thermometer to which it is adapted, combined with means for holding said tables, means for bringing the properset of tables to the front and means permitting the rotation of the tables to bring the proper table of a set to a definite readingpoint, in accordance with the reading of the wet-bulb thermometer; substantially as set forth.

2. 'In an instrument of the character described, a dry and a wet bulb thermometer, and a series of sets of hygrometer-tables each adapted to be held in an exposed position and each adapted to a definite reading of the dry-bulb thermometer, each of said sets being in dial form and bearing a character denoting the reading of the dry-bulb thermometer to which it is adapted, and each table of each set bearing a character denoting the reading of the wet-bulb thermometer to rounded by a dial havin a series of equidistant spaces, a wet an a dry bulb thermometer, a rotary frame 1n rear of said opening and carrying rollers, an arm connected with said frame and extending forwardly" into cooperative relation with said dial, and a strip of fabric mounted on said rollers and adapted to travel across said opening upon the rotation of said rollers, said strip bearing a series of sets of hygrometer-tables each set adapted to said opening and to a definite reading of the dry-bulb thermometer and bearing a character denoting the reading of the dry-bulb thermometer to which it is adapted, said dial denoting the extent to which said rotary frame must be turned, in accordance with the difierence between the readings of the dry and wet bulb thermometers, to bring the proper table of the set to the reading-point substantially as set forth.

4. An instrument of the character described comprising a supporting-frame having in its face a circular reading-opening surrounded by a dial having a series of equidistant spaces, a wet an a dry bulb thermometer, a rotary frame in rear of said opening and carrying rollers, an arm connected with said frame and extending forwardly into cooperative relation with said dial and a strip of fabric mounted on said rollers and adapted to travel across said opening upon the rotation of said rollers, said strip bearing a series of sets of hygrometer-tables each set adapted to said opening and to a definite reading of the dry-bulb thermometer and bearing a character denoting the reading of the dry-bulb thermometer to which it is adapted ,and each table of each set bearing a character denoting the reading of the wetbulb thermometer to which the table is adapted, said dial denoting the extent to which said rotary frame must be turned, in accordance with the difference between the readings of the dry and Wet bulb thermometers, to bring the proper table of a set to the readingoint; substantially as set forth.

Signe at New York city, in the county of New York and State of New York, this 19th day of July, A. D. 1906.

JAMES COWLING.

Witnesses Cius. C. GILL, An'rnun MARION. 

